The present invention relates to a vehicle collision avoidance apparatus, and more particularly, to a vehicular method and apparatus for determining and warning of potential violations of intersection traffic control devices.
A collision sequence begins when the subject vehicle (xe2x80x9cSVxe2x80x9d), through its own action or inaction, begins a chain of events which ultimately results in a collision with at least one principle other vehicle (xe2x80x9cPOVxe2x80x9d). Intersection collisions can be classified into at least four separate scenarios as shown in Table 1.
Systems have been proposed that could assist in preventing accidents of Scenarios 1 and 2 through use of an active system of collision avoidance. This type of active system is exemplified by the anti-collision radar system of U.S. Pat. No. 4,308,536 to Simms, Jr. et al., which utilizes a pulsed radar and determines whether braking or maneuvering is required to avoid a detected object. Another active system is described in U.S. Pat. No. 5,529,138 to Shaw et al., which utilizes two sets of lasers to determine the imminence of vehicular collisions. However, such systems have not gained public acceptance or popularity.
Scenario 4 involves violation of a traffic control device by a vehicle entering an intersection in contravention of the traffic control device""s indication. There are at least two types of commonly known traffic control devices used at intersections in the United States: the automatically phased traffic light and the stop sign. An automatically-phased traffic light typically cycles through three phases: red, green, and yellow. It is commonly-known that red indicates that a driver is to stop his vehicle prior to entering the intersection, green indicates that the driver is permitted to proceed through the intersection, and yellow indicates that the driver is warned that a related green signal is being terminated and a red signal is about to appear and that the driver should prepare to stop his vehicle prior to entering the intersection unless the driver is so close that a stop cannot safely be made. The stop sign indicates that a driver is to stop his vehicle prior to entering the intersection.
An object of the present invention is to reduce accidents.
A further object of the invention is to provide a method and apparatus installed in a vehicle (hereinafter referred to as an xe2x80x9cin-vehicle systemxe2x80x9d) to: (1) determine the location of the vehicle; (2) identify each intersection as the vehicle approaches the intersection; (3) determine the presence and type of traffic control device at that intersection; (4) determine whether the traffic control device associated with the intersection, in the direction of travel of the vehicle, requires the vehicle to come to a complete stop; (5) determine the acceleration required to stop the vehicle prior to its entry into the intersection; and (6) if the required acceleration exceeds a predetermined threshold level, alert the driver to brake the vehicle prior to its entry into the intersection by means of an aural, visual and/or haptic indication.
Another object of the invention is to provide a method and apparatus installed in a vehicle to: (1) determine the location of the vehicle; (2) identify each intersection as the vehicle approaches the intersection; (3) determine the presence and type of traffic control device at that intersection; (4) determine whether the traffic control device associated with the intersection, in the direction of travel of the vehicle, requires a complete stop; (5) determine the acceleration required to stop the vehicle prior to its entry into the intersection; and (6) if the required acceleration exceeds a predetermined threshold level, preempt driver control of the braking system and begin braking the vehicle automatically prior to its entry into the intersection.
Another object of the invention is to provide a method and apparatus installed in a vehicle to: (1) determine the location of the vehicle; (2) identify whether the vehicle is stopped at a phased traffic light; (3) determine the phase of the traffic light via a communications channel between the vehicle and the traffic light; (4) repetitively check to see if the vehicle is entering the intersection in contravention of the traffic light""s indication and, (5) if the vehicle does so begin to enter the intersection, then alert the driver, by means of an alarm or indication, to brake the vehicle prior to its entry into the intersection.
These and other objects are achieved by providing an in-vehicle system for determining and warning of potential violation of intersection traffic control devices. The in-vehicle system features a data storage device, a processing device, a Global Positioning System (xe2x80x9cGPSxe2x80x9d) receiver, a geographical information system (xe2x80x9cGISxe2x80x9d) digital database, an interface for entering and/or editing data into the data storage device, and an interface for alerting the driver of any impending violation of a traffic control device. The in-vehicle system may also include a visual or aural display for providing the driver with in-vehicle system-related information, a capability for communicating with an oncoming traffic control device to determine its status, and a capability for braking the vehicle without driver assistance, such as an auxiliary braking system or an interface which allows the in-vehicle system to gain control of the vehicle""s primary braking system.
The in-vehicle system features a GPS receiver which generates the latitude and longitude, heading, and velocity of the equipped-vehicle. The in-vehicle system utilizes a GIS database and correlates the vehicle""s latitude, longitude and heading, as generated by the GPS receiver, with approaching latitude and longitude of intersections. The GIS database includes a geographic location digital database that contains the positional data (e.g., latitude and longitude) and informational data (e.g., number of lanes) of all roadways within the geographic region covered by the database. The GIS database may also include intersection data (e.g., the types and locations of traffic control devices at each intersection) or such data may be present in an auxiliary datafile. The processing device deduces the distance to the intersection and closing rate information by processing vehicle location as determined by GPS or Differential GPS (xe2x80x9cDGPSxe2x80x9d), and GIS database information. This data is then further operated upon to yield a metric indicative of the amount of acceleration required to prevent vehicle entry into the intersection. The amount of acceleration required to prevent vehicle entry into the intersection is hereinafter referred to as xe2x80x9cap.xe2x80x9d
As an equipped-vehicle approaches an intersection that has been determined to have a traffic control device that requires the driver to stop (e.g., a stop sign or red traffic light), the in-vehicle system repetitively calculates a value of ap. The calculated ap is compared to a threshold level to determine the potential for driver violation of the intersection""s traffic control device.
In an alternate embodiment, once ap exceeds a threshold level, driver braking control is preempted and the in-vehicle system automatically begins applying braking power to the vehicle. In either embodiment, the overall objectives of the invention are satisfied by warning the driver of the equipped-vehicle of a potential violation of a traffic control device and thus avoiding a potential collision of the type identified in Scenario 4 of Table 1.
In yet another alternate embodiment, the equipped-vehicle""s position and lack of forward velocity are compared to the phase of a phased traffic device (ie., a traffic light). If forward motion is detected while the traffic control device is indicating red, then a warning will be issued to the driver, thus avoiding a potential collision of the type identified in Scenario 3 of Table 1.
Other objectives and features of the invention will appear in the course of the description that follows.